It flew the 1,500 kilometers in about 40 days. It is the second longest distance ever recorded for a northbound journey of Asagimadara.

Awano said he is happy to learn the butterfly flew that distance. He said he hopes it can fly even further north.

Hisashi Fujii, lecturer at Kyoto Gakuen University, said the record distance for an Asagimadara is over 2,000 kilometers during the southbound migration in summer and autumn.

The butterflies tend to breed during their northbound migration and not travel too far. The only longer migration recorded so far is about 1,800 kilometers from Taiwan to Shiga Prefecture in central Japan in 2000.